staging: most: hdm-usb: assign spinlock to local variable

This patch assigns the spinlock of struct mdev to local spinlock_t
variable to get rid of all the ugly dereferencing.

Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/hdm-usb/hdm_usb.c b/drivers/staging/most/hdm-usb/hdm_usb.c
index 8d8c72c..4156a30 100644 (file)
--- a/drivers/staging/most/hdm-usb/hdm_usb.c
+++ b/drivers/staging/most/hdm-usb/hdm_usb.c
@@ -206,14 +206,15 @@ static void free_anchored_buffers(struct most_dev *mdev, unsigned int channel,
 {
        struct mbo *mbo;
        struct buf_anchor *anchor, *tmp;
+       spinlock_t *lock = mdev->anchor_list_lock + channel; /* temp. lock */
        unsigned long flags;
 
-       spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+       spin_lock_irqsave(lock, flags);
        list_for_each_entry_safe(anchor, tmp, &mdev->anchor_list[channel],
                                 list) {
                struct urb *urb = anchor->urb;
 
-               spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+               spin_unlock_irqrestore(lock, flags);
                if (likely(urb)) {
                        mbo = urb->context;
                        if (!irqs_disabled()) {
@@ -229,11 +230,11 @@ static void free_anchored_buffers(struct most_dev *mdev, unsigned int channel,
                        }
                        usb_free_urb(urb);
                }
-               spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+               spin_lock_irqsave(lock, flags);
                list_del(&anchor->list);
                kfree(anchor);
        }
-       spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+       spin_unlock_irqrestore(lock, flags);
 }
 
 /**
@@ -397,12 +398,14 @@ static void hdm_write_completion(struct urb *urb)
        struct device *dev;
        unsigned int channel;
        unsigned long flags;
+       spinlock_t *lock; /* temp. lock */
 
        mbo = urb->context;
        anchor = mbo->priv;
        mdev = to_mdev(mbo->ifp);
        channel = mbo->hdm_channel_id;
        dev = &mdev->usb_device->dev;
+       lock = mdev->anchor_list_lock + channel;
 
        if ((urb->status == -ENOENT) || (urb->status == -ECONNRESET) ||
            (!mdev->is_channel_healthy[channel])) {
@@ -433,9 +436,9 @@ static void hdm_write_completion(struct urb *urb)
                mbo->processed_length = urb->actual_length;
        }
 
-       spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+       spin_lock_irqsave(lock, flags);
        list_del(&anchor->list);
-       spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+       spin_unlock_irqrestore(lock, flags);
        kfree(anchor);
 
        if (likely(mbo->complete))
@@ -559,12 +562,14 @@ static void hdm_read_completion(struct urb *urb)
        struct device *dev;
        unsigned long flags;
        unsigned int channel;
+       spinlock_t *lock; /* temp. lock */
 
        mbo = urb->context;
        anchor = mbo->priv;
        mdev = to_mdev(mbo->ifp);
        channel = mbo->hdm_channel_id;
        dev = &mdev->usb_device->dev;
+       lock = mdev->anchor_list_lock + channel;
 
        if ((urb->status == -ENOENT) || (urb->status == -ECONNRESET) ||
            (!mdev->is_channel_healthy[channel])) {
@@ -601,9 +606,9 @@ static void hdm_read_completion(struct urb *urb)
                        mbo->status = MBO_E_INVAL;
                }
        }
-       spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+       spin_lock_irqsave(lock, flags);
        list_del(&anchor->list);
-       spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+       spin_unlock_irqrestore(lock, flags);
        kfree(anchor);
 
        if (likely(mbo->complete))
@@ -638,6 +643,7 @@ static int hdm_enqueue(struct most_interface *iface, int channel,
        unsigned long flags;
        unsigned long length;
        void *virt_address;
+       spinlock_t *lock; /* temp. lock */
 
        if (unlikely(!iface || !mbo))
                return -EIO;
@@ -697,9 +703,10 @@ static int hdm_enqueue(struct most_interface *iface, int channel,
        }
        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
-       spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+       lock = mdev->anchor_list_lock + channel;
+       spin_lock_irqsave(lock, flags);
        list_add_tail(&anchor->list, &mdev->anchor_list[channel]);
-       spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+       spin_unlock_irqrestore(lock, flags);
 
        retval = usb_submit_urb(urb, GFP_KERNEL);
        if (retval) {
@@ -709,9 +716,9 @@ static int hdm_enqueue(struct most_interface *iface, int channel,
        return 0;
 
 _error_1:
-       spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+       spin_lock_irqsave(lock, flags);
        list_del(&anchor->list);
-       spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+       spin_unlock_irqrestore(lock, flags);
        kfree(anchor);
 _error:
        usb_free_urb(urb);